diff --git a/src/utils/ReactChildren.js b/src/utils/ReactChildren.js
index f92e5da296..154e136159 100644
--- a/src/utils/ReactChildren.js
+++ b/src/utils/ReactChildren.js
@@ -129,19 +129,19 @@ function mapChildren(children, func, context) {
   return mapResult;
 }
 
-/**
-* Count the number of children that are typically specified as
-* `props.children`.
-*/
-
 function forEachSingleChildDummy(traverseContext, child, name, i) {
   return null;
 }
 
-function countChildren(children,  context) {
-  var numberOfChildren = traverseAllChildren(children, forEachSingleChildDummy,
-    null);
-  return numberOfChildren;
+/**
+ * Count the number of children that are typically specified as
+ * `props.children`.
+ *
+ * @param {?*} children Children tree container.
+ * @return {number} The number of children.
+ */
+function countChildren(children, context) {
+  return traverseAllChildren(children, forEachSingleChildDummy, null);
 }
 
 var ReactChildren = {
diff --git a/src/utils/traverseAllChildren.js b/src/utils/traverseAllChildren.js
index 624b70c473..faf9283336 100644
--- a/src/utils/traverseAllChildren.js
+++ b/src/utils/traverseAllChildren.js
@@ -183,12 +183,11 @@ var traverseAllChildrenImpl =
  * @return {!number} The number of children in this subtree.
  */
 function traverseAllChildren(children, callback, traverseContext) {
-  if (children !== null && children !== undefined) {
-    return traverseAllChildrenImpl(children, '', 0, callback, traverseContext);
-  }
-  else {
+  if (children == null) {
     return 0;
   }
+
+  return traverseAllChildrenImpl(children, '', 0, callback, traverseContext);
 }
 
 module.exports = traverseAllChildren;